From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F272625A359; Thu, 2 Jul 2026 05:49:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782971394; cv=none; b=dkHrHeiizueRhvjYDhI6L1Z4aqsUQN6mzNaEXU1TrHmIQTQnGFAide8vEmd13CFfDB/Uzk0Ycsvp5bmPlLVYbDfenoePL/flkLUwTwiVUft8sx8KVmXZvTDVzZnl5tMXP9HwczGgPUiHsmUl2qxiaMhIKoiEM6f/kbiPOpvUUgE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782971394; c=relaxed/simple; bh=EDRUuh+6zXkDC6bSO+pBJ53xZRIngJO7/7EDLI3npoY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qD6kOfEdMJZtUcyhuT2uxET/1Qb5WZL+EYlap0M+bRAr0V+hi76OxOSrCxq2DvK/8caK3K4zJH2YeNGWd3vKHVqFq5HHkO9NH+XUuQgN8iAdKPlQU4AvuAz4BaubyBNP4KQrxQIJxZ1iIf8rhCRZrcRDhth1kfdXX1l72IMenRU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qxOXo+km; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qxOXo+km" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36E3C1F000E9; Thu, 2 Jul 2026 05:49:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1782971391; bh=drONu/zGq5+g6bv2cU4LDpfbDiQn6v9A3/zW6m6HwB0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=qxOXo+kmK1OVnezmS7rtaUvG47J+JQthmu+aN+B5Pu6M+TgeC4tsxCUAxxUEqt1Kz kclJV29CPXVXxG9ncm+BY5trqi19+rl5vcCsaArGK0qdJSPAqjHgJDBFxtHXBGdhhK WK0V/2vnsj7p41NMX8BEvvD326CieOfQJlASyj9k= Date: Thu, 2 Jul 2026 07:50:02 +0200 From: Greg Kroah-Hartman To: AceLan Kao Cc: Xu Yang , Sean Rhodes , Kees Cook , Heikki Krogerus , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] usb: core: port: Deattach Type-C connector on component unbind Message-ID: <2026070208-catapult-customize-7da3@gregkh> References: <20260611071201.1235545-1-acelan.kao@canonical.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Jul 02, 2026 at 10:26:39AM +0800, AceLan Kao wrote: > Chia-Lin Kao (AceLan) 於 2026年6月11日週四 下午3:12寫道： > > > > connector_unbind() is the mirror of connector_bind(), but it is missing > > the symmetric call to typec_deattach() that connector_bind() makes via: > > > > if (port_dev->child) > > typec_attach(port_dev->connector, &port_dev->child->dev); > > > > When a Thunderbolt dock is unplugged, two teardown paths race: > > > > 1. The component framework calls connector_unbind() first, which sets > > port_dev->connector = NULL without calling typec_deattach(). This > > leaves port->usb2_dev/port->usb3_dev in struct typec_port pointing at > > the USB device that is about to be freed. > > > > 2. usb_disconnect() then calls typec_deattach(port_dev->connector, ...), > > but port_dev->connector is already NULL, so the call is a no-op and > > port->usb2_dev is never cleared. > > > > 3. Concurrently, UCSI detects a PD partner-disconnect event and calls > > typec_unregister_partner(), which reads port->usb2_dev (now a dangling > > pointer to freed memory) and passes it to typec_partner_unlink_device() > > -> sysfs_remove_link() -> dev_name() on the freed device, corrupting > > the typec/UCSI partner state. > > > > This corruption leaves the Thunderbolt tunnel in an inconsistent state on > > the next dock hot-plug. On affected hardware the dock's I225/igc NIC fails > > to enumerate: AER fires a slot reset while the igc driver is still > > initialising ("PCIe link lost"), and the subsequent igc_reset attempt hits > > igc_rd32 on an already-detached device: > > > > igc 0000:2e:00.0 eth0: PCIe link lost, device now detached > > igc: Failed to read reg 0x0! > > WARNING: CPU: 9 PID: 129 at drivers/net/ethernet/intel/igc/igc_main.c:7005 > > igc_rd32+0xa4/0xc0 [igc] > > Call Trace: > > igc_disable_pcie_master+0x16/0xa0 [igc] > > igc_reset_hw_base+0x14/0x170 [igc] > > igc_reset+0x63/0x110 [igc] > > igc_io_slot_reset+0x9e/0xd0 [igc] > > report_slot_reset+0x5d/0xc0 > > pcie_do_recovery+0x209/0x400 > > aer_isr_one_error_type+0x235/0x430 > > aer_isr+0x4e/0x80 > > irq_thread+0xf4/0x1f0 > > > > 4. UCSI later handles the PD partner-disconnect and calls > > typec_unregister_partner(), which still sees the stale port->usb2_dev > > and tries to remove its sysfs link a second time: > > > > kernfs: can not remove 'typec', no directory > > WARNING: CPU: 6 PID: 55 at fs/kernfs/dir.c:1706 kernfs_remove_by_name_ns+0xe9/0xf0 > > Workqueue: events ucsi_handle_connector_change [typec_ucsi] > > Call Trace: > > sysfs_remove_link+0x19/0x50 > > typec_unregister_partner+0x6e/0x120 [typec] > > ucsi_unregister_partner+0x107/0x150 [typec_ucsi] > > ucsi_handle_connector_change+0x3ec/0x490 [typec_ucsi] > > process_one_work+0x18e/0x3e0 > > worker_thread+0x2e3/0x420 > > kthread+0x10a/0x230 > > ret_from_fork+0x121/0x140 > > ret_from_fork_asm+0x1a/0x30 > > > > With worse timing the same stale pointer is dereferenced after the > > backing memory is freed, turning the warning into a use-after-free. > > > > Fix the asymmetry: call typec_deattach() before clearing > > port_dev->connector, matching what connector_bind() does on the bind side. > > typec_partner_deattach() is already protected by port->partner_link_lock, > > so it serialises safely with the concurrent typec_unregister_partner() path. > > > > Fixes: 11110783f5ea ("usb: Inform the USB Type-C class about enumerated devices") > > Cc: stable@vger.kernel.org > > Signed-off-by: Chia-Lin Kao (AceLan) > > --- > > drivers/usb/core/port.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c > > index b1364f0c384ce..b4452b665f591 100644 > > --- a/drivers/usb/core/port.c > > +++ b/drivers/usb/core/port.c > > @@ -740,6 +740,8 @@ static void connector_unbind(struct device *dev, struct device *connector, void > > > > sysfs_remove_link(&connector->kobj, dev_name(dev)); > > sysfs_remove_link(&dev->kobj, "connector"); > > + if (port_dev->child) > > + typec_deattach(port_dev->connector, &port_dev->child->dev); > > port_dev->connector = NULL; > > } > > > > -- > > 2.53.0 > > > > Hi, > > Just a gentle ping, please help to review this path. It was the merge window :( Also, if you wish to have patches merged quicker, please provide review comments on other patches while you wait, what is preventing that from happening here? thanks, greg k-h